Acid spary gun



Feb. 5, 1946.

N. BOURKE ACID SPRAY GUN Filed.. March 27, 1945 Patentedl Feb. 5, 1946 ACID SPRAY GUN' Norman Bourke Gainesville, Fla.,

assigner to Board of Commissioners of. State Institutions,`

Tallahassee, Fla.

Appucamnmamh 27, 1945; serial No. 585,083 s claims. (cl. 299-95);

This invention relates to an acid spray gun particularly intended for use in spraying chemicals on slashes in pine trees in order to and increase the yield of resins and gums. The Southern ForestiExperiment Station of the United States Department of Agriculture has developed a process for stimulating the iiow of resins and gums from slashes in pine trees which involves spraying the slashes with certain chemicals. The chemical presently employed is sulphuric acid in concentrations ranging from 40% to 60%. In carrying out this process it is necessary to completely and uniformly cover the slash to the limit oiv its ability to absorb the acid without, however, leaving any excess acid which would run off with the resin or gum. The quantity of acid required for each application to a slash is from 1 to 2 cubic centimeters;

The present application describes and claims a Spray gun which is particularly suitable for discharging small amounts of atomized acid onto the tree slashes in carrying out they process described above.

Among the objects of the invention-are'to provide a spray gun which will project a finely atomized jet of acid at the proper angle for covering slashes in trees; to eliminate the necessity for usingjpumps or other mechanical devices; 'to reduce to a minimum the airpressureV required for delivery and atomization of acids by'reducing the distance which the acid must travel in reaching the atomizing nozzle; to provide an air and stimulate 1liA acid nozzle assembly which provides for automatically positioning the acid and air orices in proper relationship; to providefor ease and facility in cleaning all parts of the spray gun; to provide means to prevent the nozzle discharge orifices from becoming clogged if Vthe nozzle is accidentally brought into contact with the resi-ns or gums of a tree slash; and to provide a spray gun which can be manufactured at low cost and which utilizes many component partsf which are readily available onV the market. Other objects and advantages of the invention will be specifically referred to in `the following detailed description of one form of the invention:

In the drawing Figure 1 is a longitudinal sectional View of an acid spray gun whichv embodies my invention;

Figure 2 is an enlarged sectional view looking in the direction of the arrows 2-2 in Figure l;

Figure 3 is an enlarged sectional view looking in the direction of the arrows 3-3 in Figure l; and

Figure 4 is a side elevation view of the tubular acid nozzle.

An acid container in= the form of a. ii'ask is designatedV by the reference numeral 5 and is provided with an upper opening 6 at its upper end and a lower opening 1 in a side wal-l of the iiask near the lower end thereof. A-n air inlet tube, designated generallyv by the reference numeral 8 and which may consist of a glass tube 9 a rubber tube |10 and a glass mouthpiece. leads into the upper opening 6 of the acid container 5; An air outlet tube, designated generally by the reference numeral |12, leadsf from the upper opening 6 and may consist -of a curved glass tubel |3V and a rubber tube |4. An apertured stopper l5 of rubber or other suitable material provides a seal which prevents egress of air between the tubes 9 andv I3 and the upper opening 6 of the acid container.

The lower opening is formed by' a neck portion f6 which extends upwardlyl and outwardly from the acid container' at an angle of approximately 45 to vertical. A tubular acid conduit is received within Vthe lower opening T and makes sealing engagement therewith. The inner end [8 of" the'` acid conduit .|11 is preferably provided with a tube |19 whichextends to adjacent the bottom of the acid container 5L The air outlet tube |`2 is` preferably provided at its outer end with an adapter fitting 20 for engagement with the enlargedv lower endy 2|! oi an air passageway 22 in a nozzle body 23'. The outer end of the acid conduit |1 is fitted intothe enlarged lower end' 24` of an acid passageway 25 also located in the nozzle body 23.

The acid passageway.' 25: is` counterbored at: its upper end', as indicated by thev reference' numeral 26, to provide a tapered shoulder 211v The counterbored portion' 26 oftheA acid; passageway 25 receives a tubular acid nozzle which is designated by the reference numeral 28- and which isf best shown in Figure 4. The rear face of the acid nozzleI 28-.is frusto-conical, and itstaper is complementary to the tapered shoulder 21 as shown by the reference numeral' 2'9 in' Figure 4; The outer tip 30` of the acid nozzle is frusto-conical and to the rear of the tip 3|!t there is an upwardly stepped frusto-conical portion 3| which is provided with` longitudinally' extending grooves or flutes Y ,v

An air nozzle 33 is threaded onto the nozzle body 23 and is provided with an orice 34. The inner portion 35 of the orice 34 has a taper which is complementary to the frusto-conical portion 3| of the acid nozzle 28. The air nozzle 33 is threaded onto the nozzle body 23 until the acid nozzle 28 is clamped into .position by engage- 'o the. acid passageway nozzle 28 to the aperture 34. VAt the same time that acid is being caused to flow to the nozzle asthe'air outlet l2 to the air passageway 22, the

ment of its tapered rear face 29 with the tapered shoulder 21 of the enlarged portion 2670i the acid passageway 25 and also by engagement of its frusto-conical portion 3l with the tapered portion 35 of the orifice 34in the air nozzle 33. It

will be noted that the clamping action just referred to serves to properly center the acid nozzle 28 with respect to the acid passageway 25 and the orice 34.' TheV dimensions of the component parts of the nozzle assembly are such that simul- .Y n Y taneously with the clamping action on theV acid Yand drilling operations,

nozzle 28, the threaded flange of the airpnozzle Y 33 abuts against the shoulder 23a on thenozzle body 2.3 to thus prevent leakage. Y Y

The air passageway 22 terminates at its outer' end in an annular space 36 between the youter end of the nozzle body grooves or flutes 32 in. outer tip of the air nozzle33 'is provided with a rim orY flange portion31gwhich extends beyond the orifice 34V so vthat this orifice will not be clogged inthe event that'the nozzle assembly is accidentally brought into contactrwith gum or resin' on a treeslash. f f l e In operation the acid container is supplied with acid to approximately the levelof the index marl; 38 on its side wall. VIt will be noted that when the spray gun is held in the vertical position shown in Figure 1, the proper liquid level after lling the acid container lies just slightly below the outer tip of the acid nozzler28. The

user directs the nozzle assembly toward a tree be treated with acid, places the his lips vand blows air through 8 into the upper portion of the This creates a slight air presslash which is to mouthpiece Il to. the air inlet tube acid container 5.

sure in the acid container 5 above the level of the acid therein. This pressure is sufcient to cause acid to flow through the acid conduit l1, 25 andthe tubular acid sembly, air flows through annular space 36 and the grooves or flutes 32 in the frusto-conical por- -tion 3l 'ofY the. acid nozzle 2.8. TheV air .passing through theflutes 32 forms ya plurality of air jets `which yimpinge on the jet of acid issuing fromthe acid nozzle 28. Eiective atomization of the acid is thus obtained withinthe aperture 34 and the acid is thus directed as a fine fog vor mist onto the tree slas It has'been mentioned that when the acid container 5 is lled to the proper level very little air pressure is required to vcause a jet of acid` to issue from the acid nozzle 28. As theA supply of acid becomes depleted `within the acid container, it is possible to merelyrtilt the acid container to thus lower the nozzle assembly with respect to the level of acid within the container. While such tilting will cause some change in the angle at which the acid issues from the nozzle assembly, it will be noted that in all positions of use the atomized acid will be projected outwardly and upwardly onto the tree slash. Y The entire assembly can be readily taken apart for cleaning. The existence of the upper open- 23 andthe alr'nozzle 33,; Y This annular space 36 communicates with the the acid nozzle 28. The` Vftheformation of the ute formed by a `grindir'i'g or milling operation.

ing and their proper relative positions are automatically maintained. All portions of the nozzle assembly are readily formed by simple turning with the exception of 32 which can be readily Itwillbe apparent that it would be impossible for the'user ofY the spray gun to suck acid into his mouth if he were to accidentally inhale during use Vof the apparatus. Y

It is to be understood that the foregoing detailed description is exemplary only and that various modifications may beiresor'ted to without 'departing from the scope of lmy invention as dened by the following claims.

. of and a lower opening in Having thus described my invention, I claim:

1. An acid spray gun for spraying acid n on slashes in trees comprising an` acid container having an upper opening in the upper portion therea side wall near the lower end thereof, an acid conduit extending ulpwardly and outwardly from'said lower opening. an air inlet tube leading to said upper opening, an air outlet tube leading from said upper opening to adjacent the outery endof said acid conduit, means for sealing saidupper. .opening varound said tubes, and an atomizing nozzle assembly secured to the outer ends of said acid conduit and said air outlet tube whereby7 air introduced under pressure into said acid container through said `air inlet tube forces acid upwardly and outwardly through said aoidconduit to said nozzleassembly and air` passing to said nozzle assembly through said air outlet tube eiects atomization of such acid. 2.' An acid spray tube. 1 i Y Y *Y 3. An acid sprayrgun as described in claim'l in which said nozzle assemblyV comprises a nozzle body having an air passageway and a separate acid passageway extendingtherethrough, said acid passageway being .outwardly ared. at its nozzle having one end received in and concentrically positioned in the flared end of said-acid-passageway, the opposite end of said acid nozzle beingtapered inwardly and having flutes on the inwardly tapering surface, an air nozzle secured to said nozzle body and having an airdischarge orifice tapered complementarily `gto and receiving said tapered end of said acid nozzle-whereby said flutes provide air discharge passageways alongthe tapered end of said acid nozzle and saidfairnozzle retains said tubular acid nozzlejin'positiom s Y Y j NQRMANBKOURKE gun'as described in claim V1 in which said atomizing nozzle assembly includes 1 a tubular acid nozzle member communicating 

